Last modified: Sun 01/17/2016 03:42:24 pm
BCE

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Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.

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1. The formation of a solution can be explained using the equation G° = H° - TS°. Answer the following questions;

a) When two components are mixed and form a homogeneous mixture, the solution process is spontaneous. What is the sign of G° when two components form a homogeneous mixture?

b) What sign of H° favors a spontaneous solution process when two components form a homogeneous mixture?

c) What sign of S° favors a spontaneous solution process when two components form a homogeneous mixture?

The enthalpy term, H°, for the solution process is represented in the Figure below;

2. Using the information in the Figure above answer the following questions;

a) Is energy released or absorbed to separate the solvent particles in Step 1?

b) Is energy released or absorbed to separate the solute particles in Step 2?

c) Is energy released or absorbed when solute particles and solvent particles mix together in Step 3?

3. The sum of the energy required in Step1, Step 2 and Step 3 equals the H°, for the solution process. Mathematically this is expressed as Step 1 + Step 2 + Step 3 = solution process

What must be true about Step 3 compared to Step 1 + Step 2 for the solution process to be negative, favoring the solution process?

4. Based on the Figure which has more positional microstates (greater randomness/greater dissorder) a solute and solvent before mixing, or a homogeneous mixture of that solute and solvent?

Explain

5. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

 

6. If there is one question you would like to have answered in lecture, what would that question be?